Safety appliance for elevators or mining-cages.



PATENTED AUG. 2, 1904.

W. P. WARD. SAFETY APPLIANCE FOR ELEVATORS OR MINING CAGES.

APPLICATION FILED MAY 4, 1904.

N0 MODEL;

Witnwaeo UNITED STATES Patented August 2,1904.

PATENT OFFICE.

WVILLARD P. YARD, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 766,404, dated. August 2, 1904.

' Application filed May 4:, 1904- Serial No. 206,400- (No model.)

To a, who/1t it may OOII/(JCIIL:

Be it known that 1, \VILLAE I) PARKER \VARD, of the borough of Manhattan, city, county, and State of New York, have invented a new and useful Improvement in Safety Appliances for Elevators or Mining-Cages, which is fully set forth in the following specification.

This invention relates to elevator safety appliances, and especially to those in which a frictional resistance is interposed at the sides of the elevator-shaft; and the objects of the invention are to provide an automatic elevator safety appliance which can be actuated by the elevator-car whenever by accident or other wise its downward acceleration exceeds a predetermined amount and which is simple in construction, compact, and responds readily to changes in speed of the car.

The objects of this invention are attained by interposing an increasing frictional resistance at the sides of the cage or car as it nears the bottom of the shaft through the agency of mechanism responding to the movements of the car. For this purpose in the preferred embodiment of the invention the ordinary guides or sections thereof with which the shaft is provided and which engage the car or elevator are hinged at a suitable distance above the bottom of the shaft and are connected with automatic means actuated by the car for thrusting their lowereuds inward under the car whenever the latter has for any reason attained a predetermined downward speed. Normally the hinged guides are held in alinement with the lixed guides on the shaft and are only inclined or thrown out of aline ment when actuated by the too rapid fall of the elevator. The car is usually provided with a cross piece or pieces by which the floor of the car is reinforced, and between the guides and the ends of these pieces are provided means for taking up the shock when the car meets the inclined steel guides or bars. The means preferably employed for this purpose consists of pieces of soft metal placed at the ends of the cross-pieces, where they meet the steel guides when the latter are caused to approach each other by the action of the automatic device. The softer metal will first 5 come in contact with the steel guides and will be worn away by the friction thus generated, and to the extent represented by the force required to wear away this metal the velocity of the falling car will be reduced before the unyielding ends of the cross-bar, come in contact with the guides or bars, thus taking up the first impact of the car with the inclined guides.

Having thus described the general nature and objects of the invention, referenceis made to the accompanying drawings, which are designated merely as illustrations to assist in the description of the invention and not as delining the limits thereof.

Figure l is a side elevation, partly in section, showing the general arrangement of parts; and Fig. 2 is a plan view showing the special construction of a cross-bar.

The car 1 is supported in any suitable way above the starting-floor and runs between guides 2 2. The lower sections of these guiderails above the floor arc hinged at 3 constituting hinged guides' l 4, which may be of wood, steel, or other suitable material and are adapted to be swung in under the car when the latter falls through the operation of the automatic device at the side of the elevator.

Various automatic devices actuated by the movement of the elevator may be used to move the ends of the guides toward each other or in toward the center of the shaft; but the drawings illustrate the preferred form of the invention, in which 5 is a piston connected to the guide 4: by rod 6, and T a cylinder connected in the rear of piston with a pump 8 by means of a pipe 9. The fluid introduced into the cylinder 7 by the pump 8 escapes through pipe 10, which is of smaller diameter than that of the inlet-pipe 9, and conducted to a reservoir 11, communicating with the pump 8 by pipe 12. This arrangement permits of circulation of the same fluid through the cylinder, which is advantageous when it is desired to use oil, though other fluids may be used and the, fluid allowed to escape. The size of the exitpipe 10 relative to that of the inlet -pipe 9 is so arranged that the 'fluid pumped into cylinder 7 back of piston 5 can readily escape when the pump 8 is working at its normal speed; but when the pump is being driven much beyond its normal speed, due to a sudden drop of the car or cage, the fluid cannot escape as fast as it enters the cylinder 7, thereby pushing forward the piston 5 and hinged guide or bar 4.

The pump 8 is operated by the moving car 1 by suitable connecting means, preferably such as a rope or belt of wire 13, both ends of which are attached to the car and pass over sheaves 14, 15, and 16 at the top and bottom of the shaft, respectively, and around a drum 17, to the shaft or arbor of which pump 8 is attached by suitable connections 19 and 20.

The operation of the device thus far described is as follows: WVhen the car is running up or down at normal speed, the moving cable 13 causes the drum 17 to rotate, which in turn actuates the pump 8, which forces fluid into cylinder 7, from which it escapes as fast as it enters. maintained in a fixed position, and the guide or guides 4 4 are held in a vertical position and in alinement with guides 2 2. The car running at its normal speed will therefore be able to descend to the ground floor without interruption. hen, however, for any cause the car takes on a speed in excess of that for which the safety device is constructed, the pump 8 will be operated at an increased speed. The fluid will enter cylinder 7 through pipe 9 faster than it can escape through exit-pipe 10 and will force the piston 5 forward, causing the guides 4 4 to swing in under the car, and before the cage or car can reach the bottom of the shaft it must push the guides back into their normal position. In an extraordinarily short time the velocity of the car will be greatly reduced, duringwhich the fluid by which the pressure has been developed in cylinder 7 will have time to escape, and the car will then descend to the bottom of the shaft at a safe and reasonable speed. a v

The speed at which the pump works depends on the speed at which the elevator-car or mining-cage is moving in the shaft, and the outlet from the cylinder is so proportioned that there will always be some pressure on the cylinder when the elevator is in action. The size of the escape is so regulated that the guides will not be forced from their normal position unless the car is traveling at a dangerous speed.

In Fig. 2 is illustrated means for gradually reducing the velocity of the falling cage or car as it enters the inclined guides 4 4. The friction between the guides 4 4 and a strong cross-piece 21, by which the fioor of the car is reinforced between the guides, is relied upon to gradually diminish its falling velocity,- and thus to prevent a dangerous crash when the car reaches the bottom of the shaft. This cross-piece 21 under the floor of the car, is provided at its ends with a softer metal or alloysuch as copper, lead, tin, bismuth or equivalents or alloys of the samewhere it The piston 5 is therefore out departing from my invention.

comes in contact with the steel guides. WVhen the latter are caused to approach each other by the automatic device above described, this softer metal will first come in contact with the'guides 4 4 and be worn away by friction, the velocity of the car being greatly reduced before the unyielding bar 21-comes in contact with the guides 4 4. The first impact of the car with the guides is thus cushioned by the yielding metal 22, which greatly adds to the efficiency and the safety of the device. The contact parts have been referred to as made of metal; but they may be made of wood or other suitable material.

The whole mechanism is small and compact, occupying but a small space at the side of the elevator-shaft and below the starting-floor, and this is especially so when hydraulic pressure is used to actuate the guides.

If for any reason it is considered desirable not to interfere with the regular guides, the same object may be accomplished by placing the hinged guides elsewhere in the shaft, where they can be operated in a similar manner.

In tall buildings or in deep shafts similar appliances can be introduced at stories or stations intermediate the top and bottom.

l/Vhile hydraulic pressure in the cylinder is generally preferable, because the mechanism can he made more compact, pneumatic pressure of air or other gases may be employed, if desired.

While I prefer that there should be one or more hinged bars, as above described, on each side of the shaft arranged in pairs opposite one another, one bar or a series of bars on one side of the shaft only or bars on opposite sides not arranged in pairs can be used with- It is desirable that each bar should have a corresponding cross-piece on the elevator or lift to withstand the pressure against the side of the elevator or lift.' Furthermore, instead of the hinged bar or bars I may employ any other suitable form of friction device or means automatically controlled and operated by the movements of the car to bear against the latter and frictionally retard or obstruct the movement of the car in case of, too rapid descent thereof.

IVhat I'claim, and desire to secure by Let ters Patent, is

1. In an elevator, the combination with a car, of a friction device, automatically operated by the car, when it travels at abnormal speed, to bear against the car and retard or check the movement thereof.

2. In an elevator, the combination with a car, of friction devices automatically operated by the car, when it travels at abnormal speed, to bear against opposite sides of the car and retard or check the movement thereof.

3. The combination with an elevator-shaft, of a car, or cage, bars arranged in said shaft at opposite sides thereof and hinged at their upper ends, and means for automatically causing the lower ends of said bars to converge toward one another, whenever the elevatorca r or cage moves faster than at normal speed.

t. The combination with an elevator-shaft, of a car or cage, a bar or bars hinged at the upper end and arranged in said shaft at one or both sides thereof, and means for automatically causing the lower end of said bar or bars to incline toward the center of the shaft whenever the car or cage moves faster than at normal speed.

5. The combination with the shaft, of an elevator-car or cage, a bar or bars hinged at the upper end and arranged in said shaft at one or both sides thereof, means for causing the lower end of said bar or bars to incline toward the center of the shaft whenever the elevator-car or cage moves faster than at normal speed, and a cross-piece on the car adapted to press against said bar or bars when so inclined. I

6. The combination with the shaft, of an elevator-car or cage, a bar or bars hinged at the upper end and arranged in said shaft at one or both sides thereof, means for causing the lower end of said bar or bars to incline toward the center of the shaft whenever the elevator-car or cage moves faster than at normal speed, a cross-piece on the car having a comparatively soft material at the end or ends thereof which material bears against said bar or bars when so inclined, substantially as described.

7. The combination with the shaft, of an elevator-car or cage, of a bar hinged at the upper end and located in said shaft at one side thereof, a pump which is caused to act by the movement of the car or cage and whose speed of operation is in accordance with the rapidity of said movement of the car, and means actuated by fluid-pressure and controlled by said pump to incline said bar into the path of the car when the latter moves at greater than normal speed, substantially as described.

8. The combination with the shaft, of an elevator-car or cage, abar hinged at its upper end and located in said shaft at one side thereof, a pump which is caused to act by the movement of the car or cage and whose speed of operation is in accordance with the rapidity of movement of said car, a cylinder in which said pump generates fluid-pressure, said cylinder having an outlet large enough to relieve such pressure when the e1evator-car or cage is moving at normal speed but which is insuf ficient to relieve said pressure when the elevator-car or cage is moving at greater than normal speed, and means actuated by such excess of pressure to incline said bar into the path of the car, substantially as described.

9. In an elevator safety appliance, the combination of an elevator-car, one or more oscillatory bars, and automatic means actuated by said car for moving said bar or bars into the path of the car.

10. In an elevator safety appliance, the combination of an elevator-car, one or more oscillatory bars, automatic means actuated by said car for moving said bar or bars into the path of the 021],21I1Ll means on the car for cushioning the impact of the car with the said bar or bars.

11. The combination of an elevator-shaft, a car movable therein, a guide-rail engaged by the car, a movable bar constituting a section of said rail, and means automatically operated by abnormal speed of the car to incline said bar into the path of movement of the car.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

W'ILLARD l. \VARI).

\Vitnesses:

\VILLIAM H. L. Lee, ROBERT A. PIPER. 

